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By Forrest T. Moyer

INJURY experience and related employment information are presented in the chapter for the coal-mining, coking, oil and gas, peat, and native asphalt industries in the United States for 1964. No attempt has been made to combine these data and present injury-frequency rates reflecting the mineral-fuel industries because the hazards of the separate industries are not comparable. All rates in the text are calculated separately on data before rounding, hence component rates may not add to the total rates shown in the tables. Tabulations showing the trend of injuries and employment for all mineral industries are presented in Volume III. COAL Injury experience of the coal mining industry was improved in 1964, as measured by the declines of 1 and 14 percent, respectively, in the frequency and severity rates. Although the total number of injuries increased in 1964, a slightly greater proportional increase in man-hours worked caused the frequency rate to drop to 44.65 per million man-hours. The injury-severity rate in 1964 was 7,832 days lost per million man-hours of exposure. Employment and injury data for 1964 are based on final data for anthracite mines and preliminary data for bituminous coal and lignite mines. Fatality experience improved significantly with a record low number of 240 deaths in 1964. This total was 44 less than in 1963. The Nation's coal mines during 1964 were free of major disasters (a single accident resulting in the death of five men or more) for the first time since 1956. The

Jan 1, 1965

By J. L. Howell, D. E. Pollock, A. B. Cecala, A. D. O’Brien

Dust from worker,s clothes has been shown to be a problematic source of personal dust exposure. A recently completed effort between NIOSH and the Unimin Corporation has resulted in a quick and effective way to clean worker clothing. The process involves a booth under negative pressure with an air spray manifold to supply compressed air to blow off the dust from the clothing. The overall system is designed to meet MSHA and OSHA requirements. Results of field testing indicated that the manifold cleaned the clothes 10 times faster and removed 50% more dust than cleaning methods used by workers today.

By M Baker

Biodiversity offsets are conservation actions intended to compensate for the residual, unavoidable harm to biodiversity caused by development projects. The use of biodiversity offsets in the context of mining has significant potential for enabling mining to take place in areas with biodiversity values, where it would not otherwise be possible to meet the relevant legal tests under the Resource Management Act 1991, and potentially the Conservation Act 1987. This paper looks at the concept of biodiversity offsets (and environmental compensation generally) both in New Zealand and internationally, and considers how lessons learned overseas may be adapted for this country. In New Zealand the practice of biodiversity offsets and environmental compensation is ad hoc and variable. The challenge with biodiversity offsets is to establish a transparent and coherent means of identifying the overall priorities and objectives of adopting such an approach, as well as how the relevant values are measured and protected. Establishing a methodology for quantifying biodiversity value, and the need for clear policy guidelines on biodiversity offsets are identified as key areas in need of wider discussion.

Jan 1, 2007

By C. H. Herty

As the problem of inclusions in steel has become increasingly important, more and more attention has been paid to the source of the oxide inclusions in steel. In killed steels the oxide inclusions are traceable to the reaction of deoxidizers with the iron oxide dissolved in the steel during the refining period of the open-hearth heat. In a large class of steel known as "rimming steel" the action of the steel during solidification depends entirely on the gas evolved, and this evolution in turn is controlled by the amount of iron oxide in the liquid steel in the mold. It is therefore of great importance to be able to determine the amount of iron oxide dissolved in steel and to devise methods for the control of iron oxide in any class of steel. The object of the present investigation was to obtain a true value of the oxygen content of liquid steel. If the steel has not been deoxidized, the greater percentage of the oxygen is present as iron oxide in solution.

Jan 1, 1932

By Russell Barr, Robert E. Cook

As most mining companies are taking advantage of the high market prices for base metals such as steel, copper and zinc, numerous challenges still face them. While demand is strong from countries like China and the United States, demand is still mixed in Europe. This leads to the question of how long these high prices and overall high global demand will last. The tremendous market prices of most precious and base metals have enabled many companies to pay down a significant amount of debt accrued during acquisition and capital expenditure phases. Additionally, mining companies have been able to internally fund and engage in large projects to address future growth, (Less, 2006), thus maximizing the performance of the existing asset base, driving maintenance costs down, and improving and empowering the work-force (Mining Journal, 2006). Market prices and general efficiency gains have addressed these issues to some extent. However, critical issues still face operating managers in the mineral pro-cessing side of the industry. Energy prices, for example, continue to have a negative impact on cash costs for producing an ounce of gold or ton of a given base metal (Cummins, 2003).

Jan 1, 2007

By John F. MacDonald

From 19BS thru the present, Guy F. Atkinson Construction Company has been involved in several transportation construction projects in the Seattle area. Two of these contracts, the Mt. Baker Ridge Tunnel, and The Seattle Bus Tunnel, had unique foundation features. MT. BAKER RIDGE TUNNEL ACCESS PITS The Mt. Baker Ridge Tunnel is part of the general upgrading of the I-90 freeway between I-405 and I-5 (see Fig. 1). It is located on the western shore of Lake Washington and consists of a 1300 foot long large diameter tunnel thru Mt. Baker Ridge. The ridge consists of over consolidated silts and clays overlain by a loose to medium dense silty fine sand. The water table is perched in this upper layer of material. The clays of Seattle have a history of being very sensitive to excavation. The hills are marginally stable and numerous landslides have occurred recently in the area of the tunnel. [ ]

Jan 1, 1990

By Harry Asche

The last 12 months has seen the construction of the first Earth Pressure Balance (EPB) TBM excavated tunnel in New Zealand on the Project Hobson sewer storage tunnel for Watercare Services Limited, with the concurrent excavation of the second EPB tunnel on the Rosedale Outfall project for North Shore City Council. Together these tunnels involve a total length of 6km and follow an 8 year pause in TBM activity in Auckland. TBM performance on these two projects is thus of significant interest as there are four major tunneling projects totaling over NZ$8B being planned for Auckland, in similar ground conditions. Auckland?s bedrock is a weak sandstone/siltstone (East Coast Bays Formation), subject to infilled paleovalleys. The geology in the region has been significantly influenced by volcanic activity; 49 volcanoes are present within 20km of the city centre. The paper describes the design and construction challenges for the projects, including TBM performance, ?sticky spoil? management, and risks associated with basalt lava flows and two paleovalleys. Watercare?s Project Hobson also saw the successful implementation of a Geotechnical Baseline Report?one of the first uses of this type of document in Australasia. Rosedale Outfall is designed for high internal water pressures with varying hydraulic flows, with the risk of exfiltration explicitly addressed.

By J. Kortnik

Mining has always been, and still is, an activity which is vital for the development of mankind. This is because a predominant proportion of industrial products and energy is produced from raw materials that are excavated using mining methods. The need for environmental protection and the close proximity of urban settlements and mines in Slovenia have necessitated ever stricter requirements for the excavation of raw materials and introduction of more environmentally-friendly mining methods. This is achieved by implementing a closed eco-technological cycle of raw material excavation within the scope of mining methods. In surface mines, this means prompt reclamation of the degraded surfaces, and in underground mines the use of methods with minimized impact on the surface and on underground water. In underground mines, mining methods with backfilling installed according to the multi-barrier disposal system are the only ones that allow the possibility of implementing a closed eco-technological cycle of excavating raw materials. Various industrial waste materials are also included in the backfilling material in order to improve its strength properties. Backfilling consisting of several different waste materials is produced in the form of a composite. Before backfilling consisting of waste material composites can even begin to be used in mines, an environmental impact assessment of its suitability for mines needs to be made. In order to make such an assessment, a pressure leaching cell and an open diffusion cell were made, i.e. a pressure leachate test and a sorption test were developed. The two cells and the developed tests will enable the study of the influence of backfilling on the environment if installed in an underground mine. The pressure leachate test performed with the use of the pressure leaching cell simulates leaching from a consolidated backfill during the seeping of underground water into the backfilling material under pressure. The sorption test performed in an open diffusion cell simulates the flow of eluate leached from the backfilling material through the rock/geotechnical barrier. The two tests were developed in such a manner that they are performed either in succession immediately after one another, but they can also be performed separately at a certain time interval. The paper presents an assessment of the suitability of backfilling made of different waste material composites. Keywords: environmental impact assessment, multi-barrier disposal system, waste material composites, pressure leachate test, sorption test, pressure leaching cell, open diffusion cell, eco-technological cycle, mining methods with backfilling.

Jan 1, 2003

By Philani Larrance Ngwenyama, Ronald CW Webber-Youngman

The survival chances of trapped miners in underground mines depend on how quickly they can be located and rescued post-accident. During entrapments, emergency rescue is highly desired but can be hindered by the lack of positioning information when a fit-for-purpose missing-person locator system is not available. Various types of missing-person locator systems are available to aid search-and-rescue operations. From the wide range of the available systems, selecting the most suitable one becomes the next challenge. The available systems have not been measured if they are fit-for-purpose or not, and to what situation. This study proposes user requirements that can be used as a guideline to facilitate the system selection process. These user requirements provide a framework for the design and development of a fit-for-purpose missing-person locator system. The user requirements can also be used for evaluating the performances of a particular system, predict its success, and also drive future research toward developing new technology to enhance the capabilities of the current systems.

Apr 1, 2024

By D. Nutakor

The ability of computers to create synthetic representations of the real world in virtual reality offers a number of opportunities to enhance training methods used in the mining industry. Unfortunately, the training effectiveness of virtual reality systems currently used in the mining industry has received only limited testing. Miner Simulation (MinerSIM), an augmented reality system with integrated hypermedia suitable for training underground miners in the basics of using a jackleg drill to install rock bolts in a virtual mine environment is in its evaluation process at the University of Missouri-Rolla Experimental Mine. This paper discusses evaluation methodologies of the MinerSIM system, which consists of experimental and control groups with control students learning via traditional lecture and text formats. Preliminary results from usability tests of the first part of MinerSim, which is an online tutorial on underground rock bolting, are presented.

Jan 1, 2008

By V Barrera, A Brzovic, M Gaete, L Burgos, E Arancibia

Fragmentation is one of the most relevant parameters in the design and operation of a mine using the caving mining method. Fragmentation affects all subsequent operations, including extraction, comminution processes, secondary blasting and transportation.There are a number of different models in the literature to estimate the size of the ore fragments that report to the drawpoints; however, there is still no industry consensus about which one to use. This paper proposes a new model for predicting the fragmentation reporting to the drawpoints that is based on the geotechnical unit characteristics, extraction height and column of primary ore. The model is developed from observations of fragmentation measurements in different mine sectors of Codelco’s El Teniente mine in Chile.This work focuses on the following three steps:collecting fragmentation and hang-up data from several mine sectorsdeveloping a geotechnical block model using oriented core placed within the main geotechnical unitsanalysing the data and modelling the fragmentation process.The proposed model is used to discuss the mechanisms and the influence of preconditioning on the size of the ore fragments that report to the drawpoints.CITATION:Brzovic, A, Vallejos, J, Arancibia, E, Burgos, L, Delonca, A, Gaete, M and Barrera, V, 2016. Analysis and modelling of the fragmentation process – case studies at El Teniente Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 305–310 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Jean J. Abiassi

The Boston Marine Industrial Park (BMIP) VENT 6 project is a cut and cover tunnel, part of the Central Artery / Tunnel (CA/T) in the city of Boston. The BMIP job will serve as the south approach to the Third Harbor Tunnel crossing. The alignment is approximately 2500 Ft long and is made up of four sections starting from west to east: 1. West Tunnel 2. Boat Section 3. East Tunnel 4. Tunnel inside Vent 6 Cofferdam and connection to the Third Harbor Tunnel. The support of excavation (SOE) system for the West Tunnel, Boat Section, and East Tunnel are all a part of this project whereas the SOE for Tunnel inside the Vent 6 Cofferdam was a part of the contract for the Third Harbor Tunnel.

Jan 1, 1994

By Ruddle R. W.

Solid mattes are generally held to be either (a) eutectiferous mixtures of the component sulphides Cu2S and FeS or (b) mixtures of complex sulphides. This chapter shows that liquid mattes consist essentially of a homogeneous phase in which iron, copper and sulphur are present. The amount of sulphur is generally less than that required to account for all the metals as stoichiometric sulphides; mattes cannot therefore be regarded as mixtures of FeS and Cu2S. Some iron oxide may be dissolved in the sulphide phase and magnetite is often present as a second phase. If the sulphur content of the matte is reduced the composition enters the miscibility gap in the ternary system and either an iron- or copper-rich solution (depending upon the composition of the matte) separates as a new phase. On solidification any one of four phases (iron, copper, Cu2S and FeS solid solutions) may crystallize as primaries. The remainder of the matte solidifies as a ternary eutectic. It is possible that iron oxides enter into this eutectic. Knowledge of the ternary Cu-Fe-S system is far from complete and nothing is known of the quaternary system Cu-Fe-S-O

Jan 1, 1953

By George K. Burke

Underpinning of a structure has been traditionally expensive, time consuming, and, in many cases, caused as much settlement to the existing structure as it was trying to prevent. As underpinning is normally one of the initial tasks and on the critical path on a construction project, there is immense pressure on the subcontractor to speed up his operation so the new structure can proceed; this can cause an adversarial relationship to develop between the owner, engineers, general contractor and subcontractor. Since its introduction to the North American market in the late 1980's, Jet Grouting has not solved all these problems, but where utilized, has shown economical benefits, a faster and safer installation, and a minimal movement of the structures being underpinned. A history of the development of jet grouting is presented; a comparison of this technique versus other grouting methods, a description of the jet grouting system with emphasis on the triple rod systems; case histories of jet grouting used for underpinning and conclusions and references are included to follow the program's themes of: - Recognizing Solutions to Today's Problems - Defining Tomorrows Challenges - Putting America on a Solid Foundation

Jan 1, 1991

Often plant performance suffers as a result of poor control. Poor control leads to low mill throughputs, poor classification and less than satisfactory concentrate grades and overall recoveries. By using the appropriate control tools, substantial gains in plant performance can be made. Mintek?s MillStar and FloatStar controllers have been implemented at various sites across the world. The MillStar controller incorporates leading technology that controls process units from the mill feed through to the flotation feed. Typical results show that milling circuit throughput is increased by 6-10 % and the final product grind size is tightly controlled, thereby enhancing flotation performance. The FloatStar controller is aimed at stabilising and optimising flotation circuits. Through improved level control alone, recovery improvements of up to 1 % have been achieved. Furthermore, by using on-line grade analysers, the controller stabilises final concentrate grades, whilst maximising flotation recovery.

Jan 1, 2005

By J-M Huizenga, Q Shu, Y Lai, J Hammerli

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Baiyinnuo’er Zn-Pb deposit is a typical skarn deposit in NE China. Skarn and orebodies mainly occur between different units of the Lower Permian Huanggangliang Formation carbonates-sandstone-mudstone or within the contact between intrusions and marble. Skarn minerals are dominated by prograde garnet and clinopyroxene, and the main ore minerals are sphalerite and galena. We conducted single fluid inclusion compositional studies using laser ablation inductively coupled plasma mass spectrometry on clinopyroxene (pre-ore-stage mineral) and sphalerite and calcite (syn-ore-stage minerals). The results show that the Baiyinnuo’er fluids are distinctly different from basinal brine but similar to magmatic fluid, thereby indicating that the deposit has a dominantly magmatic origin. This interpretation has also been supported by the Cl/Br mole ratios, which remain stable (~500) in different fluid stages. The decreases for most of the elements in the fluid inclusions from pre-ore-stage clinopyroxene to syn-ore-stage sphalerite and calcite suggest that mixing with groundwater has occurred during mineralisation, with significant Zn, Pb and Ag deposition.CITATION:Shu, Q, Hammerli, J, Chang, Z, Lai, Y and Huizenga, J-M, 2015. Laser ablation inductively coupled plasma mass spectrometry study on fluid inclusions of the Baiyinnuo’er skarn Zn-Pb deposit, north-east China, in Proceedings PACRIM 2015 Congress, pp 451–456 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Empirical methods involve the scientific interpretation of real-world experience. Many problems in ground control lend themselves to an empirical approach because the mines provide us with plenty of experience with full-scale rock structures. During the past 10 years, powerful design techniques have emerged from statistical analyses of large databases of real-world pillar successes and failures. These include the Analysis of Retreat Mining Pillar Stability (ARMPS), the Analysis of Longwall Pillar Stability (ALPS), the Mark-Bieniawski rectangular pillar strength formula, and guidelines for preventing massive pillar collapses. In the process, our practical understanding of pillar behavior has been greatly enriched.

Jan 5, 1999

By J. A. Ruppert

The Bureau of Mines investigated methods of refining iron-contaminated zinc to marketable quality and developed a laboratory-scale process in which aluminum, added as a refining agent, reacted with the iron, forming solid Fe2Al which floated to the surface of the melt. Solids were separated by both filtration and centrifugation, using a unique type of "dipping" centrifuge devised during the work. Typical zinc recovery was 95 percent, and iron content of the metal was lowered from 0.37 to 0.02 percent.

Jan 1, 1967

By Rita D. Sylvester

"IntroductionThe Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting these industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue describes reports and articles published during the period January I, 1965, to December 31, 1969. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January I, 1960;' the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January I, 1960;3 the 5-year list of Bureau publications and articles from January I, 1960, to December 31, 1964.' It includes all the material in the four annual lists of Bureau publications and articles from January 1, 1965, to December 31, 1968, as well as the Bureau publications and articles for 1969."

Jan 1, 1970

By P G. Rutherford, A W. McOnie

A volcanic sequence is described from the Golden Cross Mine, Waihi, New Zealand. The sequence includes seven lithostratigraphic units comprising flow and pyroclastic units of Coromandel Group andesite and dacite and overlying Whitianga Group dacite and rhyolite which is intruded by the Golden Cross dacite porphyry and rhyolite dykes. The sequence is mineralised and is unconformably overlain by two post-mineral units, the lacustrine Waitekauri beds and Omahine Subgroup andesite.   Detailed structural analysis of mine data has identified four deformational events (D 1-D4) and related these to the gold-silver mineralising events. Faulting was coeval with the mineralization and directly controlled the development, localisation, style and geometry of the ore shoots. Mineralization developed in competent lithologies where dilation occurred during faulting. The Empire Fault is the master shear which controlled fluid flow. Mineralised veining developed in response to tectonic pulses occurring at slightly different stages as represented by the underground Empire vein complex and the open pit vein array. The mineralising events culminated with the deposition of barren calcite veins. Post-mineral movement along the Western Boundary fault appears to have offset the orebody.

Jan 1, 1995